Methods of making bags



P 1964 A. D. HOEPPNER 3,147,674

METHODS OF MAKING BAGS Original Filed Aug. 22, 1958 3 Sheets-Sheet lSept. 8, 1964 A. D. HOEPPNER 3, 7,

METHODS OF MAKING BAGS Original Filed Aug. 22, 1958 3 Sheets-Sheet 2Sept. 8, 1964 A. D. HOEPPNER 3,147,674

METHODS OF MAKING BAGS Original Filed Aug. 22, 1958 3 Sheets-Sheet 3United States Patent 6 Claims. (Cl. 93-35) This invention relates tomethods of making bags, and more particularly to methods of makingplastic bags.

This application is a division of my copending application Serial No.756,633, filed August 22, 1958, entitled Bags, now abandoned.

In my United States Patent 2,709,467, issued May 31, 1955, there isshown a bag made of flexible heat-sealable sheet plastic material, suchas polyethylene, having a closure-fiap-forming portion initiallypositioned exteriorly of one wall of the bag at the bag mouth adapted tobe folded over the mouth of the bag after the bag has been packed toclose the bag, and adapted to be opened by reversely folding it to bringit back to its initial position.

Among the several objects of this invention may be noted the provisionof methods of economically manufacturing bags similar to those describedin my said prior patent but which, after being packed, may be closed byan operation such as a heat-sealing operation, as distinguished from theclosing operation involving folding required by my prior construction,the closure as completed by this heat-sealing operation being similar tothat obtained by the folding operation for closing carried out on myprior bag. Other objects and features will be in part apparent and inpart pointed out hereinafter.

The invention accordingly comprises the methods hereinafter described,the scope of the invention being indicated in the following claims.

In the accompanying drawings, in which several of various possibleembodiments of the invention are illustrated,

FIG. 1 is a perspective view illustrating a first method for making afirst type of bag;

FIG. 2 is a perspective view illustrating a bag made by the methodillustrated in FIG. 1;

FIG. 3 is a cross section taken on line 33 of FIG. 2, thicknesses beingexaggerated;

FIG. 4 is a perspective view showing the bag of FIGS. 2 and 3 after ithas been packed and closed;

FIG. 5 is a cross section taken on line 55 of FIG. 4;

FIG. 6 is a view similar to FIG. 3 illustrating modification of the bag;

FIG. 7 is a perspective View illustrating a second method for making asecond type of bag;

FIG. 8 is a perspective view illustrating a bag made by the methodillustrated in FIG. 7;

FIG. 9 is a cross section taken on line 9 9 of FIG. 8, thicknesses beingexaggerated;

FIG. 10 is a view similar to FIG. 5 illustrating the bag of FIGS. 8 and9 as it appears after it has been packed and closed;

FIG. 11 is a perspective view illustrating another method ofmanufacturing bags of the type shown in FIGS. 2 and 3;

FIG. 12 is a perspective view illustrating a modification ice of theFIG. 11 method for manufacturing bags of the type shown in FIGS. 8 and9;

FIG. 13 is a view similar to FIG. 3 illustrating a modification thereof;and,

FIG. 14 is a view similar to FIG. 9 illustrating a modification thereof.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings.

Referring to the drawings, FIG. 1 illustrates a first method for makingbags from a continuous web 1 of flexible heat-sealable sheet plasticmaterial such as polyethyl ene. As shown therein, this web islongitudially folded to have a first wall 3 and a second wall 5 joinedalong one edge by an integral gusset 7. This folding is carried out byany suitable conventional folding means well known in the art while theweb is fed in the direction indicated by the arrow in FIG. 1. The wall 5is wider than the wall 3 and has a free marginal portion 9 whichprojects out beyond the free edge 11 of the wall 3. In accordance withthis invention, a strip 13 of flexible heatsealable sheet plasticmaterial such as polyethylene is drawn from a supply roll 15 andsuperimposed on the folded web 1 extending lengthwise thereof overlyingthe free edge 11 of the narrower wall 3 of the folded web, whereby partof the strip 13 laps the free margin of the wall 3 and part of the stripoverlies part but not all of the free marginal portion 9 of the widerwall 5 of the web. This leaves part of portion 9 projecting laterallyoutward beyond the strip 13.

The folded web 1 with the strip 13 superimposed thereon is thenheat-sealed and segmented on transverse lines at bag width intervals todivide it into individual bags B (one of which is illustrated in FIG. 2)having heatsealed seams at both sides. Each heat-sealed bag side seam isdesignated 19. Each line of segmentation, these lines being designated21 in FIG. 1, lies between a side seam 19 of one bag and the side seam19 of the next bag segmented from the folded web. The strip 13 isheat-sealed and segmented along with the folded web, the ends of thestrip segments being heat-sealed to the bag at the sides thereof byseals indicated at 19a which extend throughout the width of the stripsegments on the same lines as seals 19.

As a result of the above-described operations, each bag B has a firstWall 23 (which may be termed the front wall) derived from the wall 3 ofthe folded web 1, and a second wall 25 (which may be termed the backwall) derived from the wall 5 of the folded web. The front Wall 23 andback wall 25 are joined at the bottom of the bag by a gusset 27 derivedfrom the gusset 7 of the folded web 1, and are joined along the sides ofthe bag by the heat-sealed side seams 19. The back wall 25 is of greaterheight than the front wall 23, and projects beyond the upper or mouthedge of the front wall. The projecting portion of the back Wall 25(derived from portion 9 of the folded web 1) is designated 29 and themouth edge of the front wall 23 is designated 31. Each bag B also has astrip segment or band 33 (derived from strip 13) extending across thebag from one side edge to the other, overlying the mouth edge 31 of thefront wall 23. The ends of band 33 are heatsealed at 19a to the sideedges of bag B, the band otherwise being free of the bag. Portion 29 ofthe back wall '25 projects beyond the upper edge of the band 33.

The bag B shown in FIGS. 2 and 3 is adapted to be packed with an itemsuch as indicated at 37 in FIG. 5 by inserting the item between theupper portion 29 of the back wall 25 and the band 33, and then betweenthe upper portion of the front wall 23 and the back wall 25. The portionof the back wall which extends beyond the band is free to be gripped tofacilitate opening up of the mouth of the bag for insertion of the itemto be packed therein. The bag is adapted for being packed automaticallyor semiautomatically, utilizing a device having means for gripping theportion of the back wall 25 which projects beyond band 33, leaving theband and the front wall 23 free, the device also having means forblowing air under the band and between the front wall and the back wallfor blowing the bag open. The arrangement is also useful for handoperations, if desired, the projecting portion of the back wall beingreadily gripped by hand for opening up the mouth of the bag.

After the item has been placed in the bag, the band is heat sealedadjacent its upper margin to the projecting portion 29 of the back wallalong a line extending transversely across the bag above the upper edge31 of the front wall 23, as indicated by the arrows 39 in FIG. 3 and at39 in FIGS 4 and 5, the portion of the back wall and the band above thisseal 39 being simultaneously trimmed off so as to give a neat finishedappearance to the package. The final package is then similar to acompleted package comprising a bag shown in my prior Patent 2,709,467 inthat the mouth of the bag is closed by a closure-fiap-forming portion(constituted by the band 33) which extends across the front of the baghaving its ends heat sealed to the bag at the side edges thereof. Thisclosure-fiap-forming portion 33 is adapted to be folded back to open upthe bag by inserting the fingers thereunder adjacent the sides of thebag, and turning it inside out.

FIG. 6 illustrates a modification of the bag shown in FIGS. 2 and 3,differing from the latter in having a flat ungusseted bottom asindicated at 41, instead of having a gusseted bottom as shown in FIGS. 2and 3. Bags such as shown in FIG. 6 may be made in the same manner asshown in FIG. 1, except that web 1 is folded in such manner that walls 3and 5 are joined by a single fold instead of by the gusset 7.

FIG. 7 illustrates an alternative method in which the strip 13, insteadof being superimposed on the folded web 1 overlying the edge 11 of thenarrower wall 3, is fed in between the wall 3 and the wall 5 underlyingthe edge 11 of wall 3. Otherwise, the operations are the same as in FIG.1.

FIGS. 8 and 9 illustrate a bag B1 made according to FIG. 7, and FIG. 10illustrates a completed package comprising the bag B1. The bag B1 issimilar to the bag B of FIGS. 2 and 3, and the completed package issimilar to the package shown in FIGS. 4 and 5, except that the band,which is designated 33a in FIGS. 8-10 to distinguish it from the band ofFIGS. 2-5, lies between the upper portion of the front wall 23 and theback wall 25'. To open the package B1, the fingers are inserted betweenthe upper portion of the front wall 23 and the band 33a and then underthe band to fold it back.

It will be understood that the bag B1 may be made with an ungussetedbottom, as in the bag shown in FIG. 6.

FIG. 11 shows a method of this invention for making the bags B, whichdoes not require the feeding of the tape 13 as in FIG. 1. As shown inFIG. 11, a web 51 (wider than the web 1) is used, and this web 51 islongitudinally folded to have a first wall 53 (corresponding to wall 3)and a second wall 55 (corresponding to wall 5). FIG. 11 shows thesewalls joined by a single fold 57 instead of a gusset, but it will beunderstood that the walls may be joined by a gusset. Wall 55 has aportion 59 projecting out beyond the free edge 61 of wall 53,

and a marginal portion 63 of the web is folded over on a longitudinalfold line 65 to overlap the free margin of wall 53. As the folded web 51is fed forward, the foldedover marginal portion 63 is slit as by a blade67 along a line 69 adjacent the fold 65. Thus, a strip 71 is separatedfrom the web lying in the same position as occupied by the strip 13 inFIG. 1. The part of the foldedover marginal portion 63 outward of theslitting line 69 folds back outward so that the wall 55 has portion 73projecting out beyond the strip 71. The end result is a folded web likethat shown in FIG. 1 with a strip super imposed thereon in the samemanner as in FIG. 1, and this is converted into bags B in the samemanner as shown in FIG. 1.

FIG. 12 shows a method similar to the FIG. 11 method for making bags B1of FIGS. 8 and 9, which does not require the feeding of tape 13 as inFIG. 7. The FIG. 12 is essentially the same as the FIG. 11 method exceptthat the marginal portion 63 of the web 51, instead of being folded tooverlap the free margin of wall 53, is folded over to underlie the freemargin of wall 53. Consequently, the strip 71a separated by blade 67lies in the same position as occupied by the strip 13 in FIG. 7. The endresult is a folded web like that shown in FIG. 7 with a strip betweenthe walls, and this is converted into bags B1 in the same manner asshown in FIG. 7.

FIG. 13 shows a modification of the bag B shown in FIGS. 2 and 3 inwhich the width of band 33 is such that the band projects beyond theupper edge of the wall 25. FIG. 14 shows a modification of the bag B1shown in FIGS. 8 and 9 in which the band 33a projects beyond the upperedge of the wall 25. These types of construction may be desirable, forexample, in instances where it is desirable to hold the bag in a packingdevice by gripping the band rather than the wall 25. They may be made bymethods similar to those illustrated in FIGS. 1, 7, 11 and 12.

In view of the above, it will be seen that the several objects of theinvention are achieved and other advantageous results attained.

As various changes could be made in the above methods without departingfrom the scope of the invention, it is intended that all mattercontained in the above description or shown in the accompanying drawingsshall be interpreted as illustrative and not in a limiting sense.

I claim:

1. The method of making bags comprising folding a continuous web of bagmateriallongitudinally to provide a first wall and a second wall withthe second wall wider than the first wall, folding the web such that amarginal portion thereof is folded back over from the second wall towardthe first wall, slitting the marginal portion longitudinally to providea strip extending lengthwise of the web in position lapping the freeedge of the first wall, then segmenting the folded web with the stripthereon at bag width intervals and side-seaming the segments, the stripbeing simultaneously segmented and having its ends secured to thesegments at the side seams.

2. The method of claim 1 wherein said marginal portion is folded tooverlie the free edge of said first wall and said strip accordinglyoverlies the free edge of the first wall.

3. The method of claim 1 wherein said marginal portion is folded to liebetween the walls and said strip accordingly lies between the walls.

4. The method of making bags comprising folding a continuous web ofheat-scalable plastic longitudinally to provide a first wall and asecond wall with the second wall wider than the first wall, folding theweb such that a marginal portion thereof is folded back over from thesecond wall toward the first wall, slitting the marginal portionlongitudinally to provide a strip of heat-scalable plastic extendinglengthwise of the web in position lapping the free edge of the firstwall, then simultaneously heat-sealing and segmenting the folded webwith the strip thereon on transverse lines spaced at bag width intervalsto form bags with heart-sealed side seams, the strip beingsimultaneously segmented and having its ends heat-sealed to the bags attheir side seams.

5. The method of claim 4 wherein said marginal portion is folded tooverlie the free edge of said first wall and said strip accordinglyoverlies the free edge of the first wall.

6. The method of claim 4 wherein said marginal por- UNITED STATESPATENTS Bartelt June 23, 1953 Sylvester Feb. 17, 1959 Walters Mar. 22,1960 Hoeppner Dec. 25, 1962

1. THE METHOD OF MAKING BAGS COMPRISING FOLDING A CONTINUOUS WEB OF BAGMATERIAL LONGITUDINALLY TO PROVIDE A FIRST WALL AND A SECOND WALL WITHTHE SECOND WALL WIDER THAN THE FIRST WALL, FOLDING THE WEB SUCH THAT AMARGINAL PORTION THEREOF IS FOLDED BACK OVER FROM THE SECOND WALL TOWARDTHE FIRST WALL, SLITTING THE MARGINAL PORTION LONGITUDINALLY TO PROVIDEA STRIP EXTENDING LENGTHWISE OF THE WEB IN POSITION LAPPING THE FREEEDGE OF THE FIRST WALL, THEN SEGMENTING THE FOLDED WEB WITH THE STRIPTHEREON AT BAG WIDTH INTERVALS AND SIDE-SEAMING THE SEGMENTS, THE STRIPBEING SIMULTANEOUSLY SEGMENTED AND HAVING ITS ENDS SECURED TO THESEGMENTS AT THE SIDE SEAMS.